The structure of conventional book, which is bound by plastic coil or spiral, is quite simple and also practical, such as a cheaper notebook or address book; however, the exposed plastic coil or spiral actually influences the appearance and the quality thereof. For improving the appearance, it is developed to hide the plastic coil or spiral inside the book. In a process, a spiral-bound book is fabricated first and then the book is covered by cardboard so that the book is composed of a cardboard cover, a spiral and plural inner leafs, wherein the plural leafs are bound by the spiral and then the cardboard is adhered inside the cover. Through this method, the book's appearance becomes more beautiful; however, the book still might be torn or be separated from the cover owing to the structure of the book is composed of spiral and paper. Another process is to additionally stitch a leather layer for covering the exposed spiral, in which the book's structure includes a leather layer, a plastic front cover, a plastic back cover, a spiral, and plural leafs, wherein the plastic front cover, the plastic back cover and the leafs are bound by the spiral to form a book and the leather layer is stitched to cover on the exposed spiral. Through this method, the structure of the book becomes more durable; however, the spiral might still be exposed owing to a loosening of the stitch, and further, the stitches also might influence the appearance.
If using a cover to cover the spiral or coil-bound book, the outer leather layer should be bought additionally, and the conventional cover structure of book, as disclosed in R.O.C. Patent no. M255159, is formed by high frequency melting lining leather layer, left positioning plate, right positioning and cover leather layer together, inwardly folding the two edges and stitching for fixing, and then the upper and the lower edges of the leather layer which are previously reserved are inwardly folded to form a folding for stitching and fixing so that the edges can be protected from destruction. The areas of the right part and the left part of respective the lining leather layer and the cover leather layer are larger than those of the left and the right positioning plates so that after the high frequency melting, the lining leather layer and the cover leather layer may form a left folding pieces and a right folding piece. When the pieces are inwardly folded and stitched, a left pocket and a right pocket are formed to provide the spaces for inserting the front and the back covers of paperback or spiral-bound book. In other embodiment, the loose leafs are bound by a binder riveted inside the book, but, in this method, the material for forming the cover becomes more because it needs to reserve the leather for forming the folding edges and the left and the sight pockets, and further, after high frequency melting, it still needs at least two stitching procedures for finishing the product. Therefore, obviously, the structure still can be simplified and improved, and further, for riveting the binder, a harder plate should be added which also increase the cost and manufacturing process.